Apparatus for skimming liquids



Aug. 4, 1936. J. L. ALDEN :1 AL 2,049,937

APPARATUS FOR SKIMMINGLI QUIDS ,liled JuTy 20,1933

INVENTORS a. L-ALDENI HA. ANDERSON v :43 Q (um ATTORNEY Patented Au 4, 1936 uNmED STATES PATENT OFFICE APPARATUS FOR SKMMING LIQUIDS Application July 20, 1933, Serial No. 681,270

3 Claims.

This invention relates to an apparatus for skimming liquids, and more particularly to an apparatus for skimming floating dross accumulation from molten lead contained in a receptacle. The invention has been found particularly useful for skimming floating dross accumulation from a freshly poured charge of lead alloy in the cylinder of a cable sheath extrusion press. The practice heretofore, in certain cases,'has been to manually remove the dross accumulation from the charge of alloy by raking or scraping it off. It is very difficult by this manual method to avoid leaving impurities in. the molten metal which would deleteriously afiect the sheath of the finished cable.

An object of this invention is to provide an improved method of and apparatus for skimming liquids which is simple and efficient.

One form of apparatus embodying the features of the invention and by means of which the improved method may be practiced comprises, as applied to a lead'alloy extrusion press, a shear blade fixed to a power driven pivotal arm andarranged to slide along an arcuate path across the upper end of the lead extrusion cylinder. The aperture in the blade has a shear edge adapted when the blade is laterally moved across the upper end of the cylinder to skim .the floating frothy accumulation or dross from the molten lead charge and carry it over a chute. The shear blade and the arm provide a dam of suitable depth surrounding the uppenend of the cylinder chamber for permitting overfilling of the chamber, thus confining the dross which is floating above the end of the chamber so that it can be completely skimmed off and thereby permitting a maximum charge of cleared molten lead to be contained in the chamber. In a second embodiment of the invention the shear blade instead of being moved along an arcuate path across the upper end of the lead extrusion cylinder is moved thereacross along a straight path by a hydraulically actuated reciprocable motor. I

The invention will be more clearly understood by referring to the following detailed description, read in conjunction with the accompanying drawing forming a part thereof, in which Fig. 1 is a plan view of a skimming apparatus embodying the features of this invention shown applied to the cylinder of an extrusion press;

Fig. 2 is a vertical fragmentary section taken on the line 2-2 of Fig. 1, and

Fig; 3 is a plan view of another embodiment of the skimming apparatus of this invention.

Referring now to the drawing in detail, particularly to Figs. 1' and'2, which represent one embodiment of the skimming apparatus of this invention designed to be. applied to a lead alloy extrusion press for use in forming a sheath around -5 a telephone cable, the reference numeral l0 designates, fragmentarily, a lead extrusion press cylinder, the cylinder having a chamber ll containing a charge l2 of molten lead alloy (Fig. 2). A ram adapted to enter the chamber l I from above 10 and extrude the charge of lead around a cable by means of a suitable die, included in the press, and said die have not been shown since they are not believed to be necessary to a complete under-;

standing of'the present invention. A bracket I3, 15

shown fragmentarily in Fig. 2, is secured to the upper end of the cylinder 10 by a pair of clamping bands It, only one of which is shown in thedrawing. Pivoted as indicated at l 5 on the bracket I3 is an arm I8 extending over the upper surface of 20 the cylinder Hi, the outer end of the arm being provided with an elongated arc shaped opening l9, opposite ends of which are semi-circular with their centers coinciding with an imaginary curvedline intersecting the center of the cylinder I0 and whose center is the axis of the pivot l5. Fixed to the under surface of the arm l8 and extending around the portion thereof having thev elongated opening I9 is a shear blade 20 having an opening 2| at one end, which is centered with one end of the opening IQ of the arm and normally centered as shown in Fig. 1 with the center of the cylinder Ill. The opening 2| in the shear blade 20 is provided with a continuous shear edge 22 at the lower surface of the blade, the edge lying slightly outside of the diameter of the chamber ll of the cylinder l0 and extending at a suitable angle to the upper surface of the blade at a point inside of the opening in the arm H3. The opposite end of the shear blade 20, indicated by the numeral 23 (Fig. 1), with the semi-circular wall of the corresponding end of the opening IQ of the arm 18 serves as a pan for receiving the skimmed dross accumulation in the operation of the apparatus. Fixed to the upper end surface of the cylinder 10 is a finished plate 25, having an opening coinciding with the diameter of the chamber l l of the cylinder, upon which the lower surface of the shear blade 20 is arranged to slide when the arm I8 is moved about its pivot l5.

Referring particularly to Fig. 2 it will be observed that the angularly disposed inner periphery of the opening in the shear blade 20 extending upwardly from the shear edge 22 thereof and the vertical inner peripheral wall of the opening '10 I8 to move it about its pivot l comprises a suitable speed reducing unit indicated in general by the numeral 26 operated from a reversible electric motor 21. A slow speed shaft 28 of the unit 25 has fixed thereto a gear pinion 29 which meshes with a segmental internal gear 32 having its axis coinciding with the pivot l5 of the arm l8 and fixed to the under surface thereof and arranged to slide on the finished plate 25, the shear blade and the arm being cut away as indicated at 20 33 to permit the mounting of the gear on the arm. Upon closing a suitable circuit (not shown) by the depression of a switch button included in the circuit, the motor 21 will be driven in one direction and the gear pinion 29 will rotate in a clock- 5 wise direction, thereby causing the segmental internal gear 32 to move about its axis I5 in a direction similar to the pinion, carrying with it the arm l8 and the attached shear blade 20. This will cause the shear blade 20 to be moved along an'arcuate path from the full line normal position to the broken line position (Fig. 1), thereby cropping or skimming the accumulated floating dross, indicated by the' numeral 34, from the charge l2 of molten lead alloy contained in the chamber ll 35 of the cylinder [0, the skimmed dross in the advance of the shear blade being moved partly onto the receiving pan portion 23 of the bladeand the opening 2|. of the blade being moved over a chute skimmed dross will then fall either by gravity through the openings in the am It and the shear blade 20 or it is scraped from the pan 23 by the operator onto the chute 35 andslides into a receptacle (not shown).

The skimming apparatus is left in this position over the chute 35 until the charge l2 of molten lead has been extruded by the downward movement of the ram (not shown) into the cylinder ll. Thereafter the ram is withdrawn and the operator then depresses another switch button and the motor 21 is operated in a reverse direction to return the arm l8 and the attached shear blade 20 to its normal position. Thereafter another charge l2- of -molten lead alloy is deposited in thechamber II and the operation of removing the dross accumulation which floats to the top of the charge is repeated. The arm l8 carrying the shear blade 20 is equipped with an-indicator point 36 and the cylinder with gauge members 31 and 38 which serve as visual indicators to the operator when they are properly alined in the two positions of I the arm l8, that the shear blade, inone case, the full line normal position thereof, is properly positioned with the opening 2| thereof in the shear blade and the means for actuating it. At

35 attached to the bracket IS. The.

the upper end of the cylinder II is a frame ll which is fixed to the cylinder by means of angular shaped clamping plates I, one arm of the plate fitting under and abutting an annular flange 42 on the cylinder and the other arm of 5 g the plates abutting the under surface of oppositely disposed longitudinal members 43 of the frame, the frame being clamped in position by bolts 44 extending through the plates and the longitudinal frame members. Opposite ends of 10 the frame members 42 are rigidly connected together by cross members 45. Interposed between the upper surface of the cylinder II and the lower surfaces of the longitudinal frame members 43 is a finished plate 48 having an opening coincid- 15 ing with the diameter of the chamber ll of the cylinder. The opposed inner vertical faces of the longitudinal frame members 43 are provided with slideways 49 upon which is arranged to slide in a straight path a shear blade 50 having an 20 opening 5| provided with a shear edge 52 similar to the shear edge 22, shownin Figs. 1 and 2, the lower surface of the blade sliding upon the hed plate ll. Gib plates 55 and end cross 7 pieces 55 all fixed tothe shear blade 55 andex- 25 tending upwardly from .the upper surface of the blade, form a surrounding wall around the opening 5| of the blade for the same purpose as the vertical inner peripheral wall of the opening I! inthearm ll,showninFigs. 1and2. ItwillsO also be noted that the opening 5| pf the blade is arranged at one end thereof to provide a we ceiving pan 51 for the sklmmeddross accumulation 34, in the operation of the apparatus. Gonnected to the right end of the shear blade 55, as 35 viewed in Fig. 3, is a piston rod 58 of a hydraulic cylinder 59 which may be connected to a suitable motive fluid supply source, including valve mechanism (not shown) fondjrecting the motive fluid I to one end'or the other of the cylinder for mov- 0 ing the shear blade in opposite directions. In the operation of the apparatus, shown in Fig. 3, the, shear blade 5|! is moved in a straight path toward the right to the position indicated in broken lines of the opening 5| thereof, and in a man- 5 ner similar to that of the shear blade 25. of Figs. 1 and 2 skims the floating dross accumulation 34 from the charge l2 of molten lead alloy contained in the cylinder l I, the skimmed dross then falling either by gravity through the opening of the blade or it is scraped from the pan '51 by the operator into achute and thence intoa receptacle (not shown).

From the foregoing it will be obvious that the several described embodiments of the skimming 55 apparatus which are simple in construction have a very practical application where it is desired to thoroughly skim floating dross accumulation expeditiously from a receptacle containing molten lead alloy. 60

Although this invention has been described in connection with a cable sheath extrusion press, it is to be understood that the invention is capable of many other applications. Therefore, the invention should be limited only by the scop 55 of the appended claims. 7

What is claimed is:

1. The combination with an open top cylinder of an extrusion press of an apparatus for skimming dross accumulaflon from molten metal in 7 said cylinder comprising a pivot-11y mounted arm having a portion provided with an elongated aperture-positionedabove the top of said cylinder, a plate fixed to t-he under surface of saidarm portion and slidable upon theupperjend 15 surface of said cylinder, said plate having an aperture disposed at one end of the elongated aperture in the arm portion andprovided with a shearing edge extending around the metal in the normal position of the arm, the surrounding walls of the apertures forming a dam for confining an overfill of the metal deposited in said cylinder, and means for actuating said pivotal arm for skimming the dross accumulation confined by the dam from the molten metal.

2. The combination with an open top cylinder of an extrusion press of an apparatus for skimming floating dross accumulation from molten metal in said cylinder comprising an arm piv- I otally mounted on said cylinder having an outer end thereof provided with an elongated aperture positioned above-the top of said cylinder, a plate fixed to the under surface of said outer end of the mend slidable upon the upper end surface of said cylinder, said plate having a circular aperture disposed at one end of the elongated aperture of said outer end of the arm and provided with a continuous shearing edge extending around the molten metal in the normal position of said arm, the surrounding walls of the aperaccumulation confined by the dam from the a 'molten metal.

3. In an apparatus for skimming dross accumulation from the top of liquid material, an open top receptacle for containing the liquid material, movable'means provided with an elongated aperl0 ture positioned above the upper end surface of the receptacle, a plate fixed to the under surface of said means extending the length thereof and slidable upon said surface of the receptacle, said plate having an aperture disposed at one end 15 of the elongated aperture in said means provided with a shearing edge extending around the material in the-normal position of said means, the oppomte end of said plate having a. horizontal plane surface eifective to receive the skimmed 20 dress in the advance thereof, and means for actuating said movable means for akimming the dross accumulation from the liquid material.

' JOHN L. ALDEN.

mm a. aunnason. 

